A vacuum system (20) includes an enclosure (22) having a vacuum-tight wall (26) and an internally threaded aperture (66) through the wall (26). A tip-off fitting (24) has a base (50) with a bore (52) therethrough. a hollow tube (62) fixed to the base (50) with a vacuum-tight seal. such that an interior (64) of the tube (62) is in communication with the bore (52) in the base (50). and an externa...

A vacuum system (20) includes an enclosure (22) having a vacuum-tight wall (26) and an internally threaded aperture (66) through the wall (26). A tip-off fitting (24) has a base (50) with a bore (52) therethrough. a hollow tube (62) fixed to the base (50) with a vacuum-tight seal. such that an interior (64) of the tube (62) is in communication with the bore (52) in the base (50). and an externa...

A new type of improved solar cooker based upon the use of a single vacuum tube is presented in this paper. The proposed cooker utilizes a solar collector consisting of parallel plane rectangular glass mirror strips mounted inside a wooden frame and requiring one dimensional solar tracking through a common driver. The proposed design can be either installed over the roof top of a house or near a...

In the present paper, several issues concerning the second law of thermodynamics, Maxwell’s demon and Landauer’s principle are dealt with. I argue that if the demon and the system on which it operates without dissipation of external energy are made of atoms and molecules (gas, liquid or solid) in thermal equilibrium (whose behaviour is described by a canonical distribution), then the unavoidabl...

INTRODUCTION The validation process is essential in accredited clinical laboratories. Aim of this study was to validate five kinds of serum vacuum tubes for routine clinical chemistry laboratory testing. MATERIALS AND METHODS Blood specimens from 100 volunteers in five different serum vacuum tubes (Tube I: VACUETTE, Tube II: LABOR IMPORT, Tube III: S-Monovette, Tube IV: SST and Tube V: SST II...

An aspiration system, incorporating a regulated vacuum pump, was used to examine, in vitro, some factors that may affect oocyte collection. In an open aspiration system, as the length of the needle was increased, or the internal diameter decreased, the velocity (and flow rate) of aspirated fluid decreased. There was a difference, however, between experimental flows and those predicted by Hagen-...